Following a repair for a no start issue on my a4, it now starts but not well (sometimes). I am experiencing long cranks (sometime takes a couple tries) mostly after the car has been warmed up and then sits about an hour and is started again. This also happens less but sometimes after the card has fully cooled. Dealer seems uninterested in working on the issue. Dealer has replaced injectors, plugs, temp sensor, fuel pressure regulator and done carbon cleaning.

Any thoughts???

 

Try the starter? Your starter might be messed up.

 

Thanks - But battery and starter seem fine - always get a nice hardy crank - just sometimes take too long to actually start.

 

Sounds like a fuel delivery problem but the dealer has replaced everything but the fuel pump. Can you smell gas when trying to start the car? Has the fuel filter been replaced?

 

Don't smell any gas. I am also suspecious of the stuff the dealer did, in that I did not have this issue prior to the actual no start issue, that they fixed. I am just out of ideas and the dealer has no interest in helping me. Also - No OBD codes have ever been stored. Thanks

 

Sorry - Missed your last line - No the fuel filter has not been replaced. Whay would you suspect this? Car seems fine once started. Is this hard to do?

 

Sounds like a fuel related issue, if your not into doing your own work. First I'd find some other shop, your guys seem to just be taking your money. Check your fuel pressure, if it's low you have an idication where to start. Seems like that was the direction they were heading. Low pressure could be a plugged fuel filter or weak pump. Ask your dealership to check for any related TSB's on the car. Has the car ever thrown any codes? (MIL light)

 

sorry, i just saw that no codes were stored. by temp sensor you mean Coolant temp. sensor or thermoswitch?

 

Sorry for slow reply...have a lot to do at work. A dirty fuel filter will cause a reduction in fuel output from the fuel pump. A clogged fuel filter will totally block the flow of gas to the engine. The fuel pressure should be easy for you or any mechanic to check. Just connect a guage to the shrader vavle on the fuel rail and take your readings while trying to start the car. I don't know what the pressure should be (I haven't had any reason to look it up...you can probably find it on this forum). If you have good fuel pressure, I would begin checking out the throttle body.

The reason we think it is a fuel problem is becusae the car starts but after long cranking periods. Since it starts we know that you are getting air and that you have spark. Back in the old days a common problem that caused slows starts was throttle body/plate positioning which was controlled by temperature. This is probably why the dealer changed the temp sensor. There is more than one temp sensor on these cars (see this post). Do you know which one they changed?

 

dafrazi you've got some good points, but....i've been fooled by a condition similar to this before at my shop. The car had a faulty cts...it wasn't throwing a code either, but since the sensor was open, the ecu believed the cars temp. was -34degrees. The car actually kept flooding itself out while trying to start, and even more surprising It didn't smell gas the slightest bit.